[Biojava-dev] [BioSQL-l] Problems in DB2 with VARCHAR, TEXT and CLOB using BioJava

Hilmar Lapp hlapp at gmx.net
Sat Jul 11 07:47:34 EDT 2009


Hi Florian:

On Jul 9, 2009, at 11:16 AM, Florian Mittag wrote:

> [...]
> 2) Change the data type to something comparable with "=", like  
> VARCHAR.

That's the way to go. The reason they are not VARCHAR in MySQL is  
because it is limited to 256 characters there.

> [...]
> Although VARCHARs in DB2 can have a length of theoretically 32767,  
> in reality
> they are limited by the page size of the database, which can be 32K at
> maximum. Since this particular table "reference" has three columns  
> of this
> type, the sum of their lengths must not exceed 32767, so they could  
> only be
> something like VARCHAR(10000).

That sounds great though. You may have noticed that the columns are  
all of type VARCHAR in the Oracle version of the schema with the  
following widths:

        Title                VARCHAR2(1000)
        Authors              VARCHAR2(4000)
        Location             VARCHAR2(512)

That has always served me well. Feel free to use larger widths though  
if you think you need them.

	-hilmar
-- 
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: Hilmar Lapp  -:-  Durham, NC  -:-  hlapp at gmx dot net :
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